Final answer:
An infant is typically able to sit unsupported at around 6 months of age.
Step-by-step explanation:
The expected age for an infant to be able to sit unsupported is around 6 months. By this age, an infant is typically able to pull themselves into a sitting position and sit unsupported for brief periods of time. By the end of the first year, most infants can stand while holding onto furniture or someone's hand, showing further development in their motor skills.